What size firms are appropriate for shared office concepts?

Conventional thinking was that small and rapidly growing companies, or companies that were uncertain about longevity of project would rent shared office space.

This limited the shared office market to companies or divisions under 10 people. Now huge firms like Amazon who just rented out an entire WeWorks at 34th Street and Microsoft renting shared office space near the Watson project in the east village.

Time will tell how many other firms follow.